Just because it wouldn't be traumatizing to you doesn't mean it cannot be traumatizing. Different people have different levels of tolerance. If you harass and humiliate your child by making up bullshit tasks for them to do, they might grow up with trust issues that at least partially stem from you, an authority figure, lying to them and treating them with disrespect for your own entertainment. If that were the only bad thing you ever did to your kid, maybe it would be an overreaction, but behaviors like that don't usually exist in isolation - if you're bullying your kid for fun, it's probably not a one-off.

You can try to rationalize to yourself that your behavior is okay, but it won't make your adult children visit for the holidays again. Childhood trauma can be healed, usually by cutting the shitty people from your childhood out of your life and learning to love and trust yourself and the family you choose.

Tl;Dr: If you want your kids to love and respect you when they grow up, treat them with love and respect when they're kids.